/*
* Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
* 
* Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
* 
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
* 
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
* 
* @APPLE_LICENSE_HEADER_END@
*/
/* ====================================================================
* Copyright (c) 1995-1999 The Apache Group.  All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in
*    the documentation and/or other materials provided with the
*    distribution.
*
* 3. All advertising materials mentioning features or use of this
*    software must display the following acknowledgment:
*    "This product includes software developed by the Apache Group
*    for use in the Apache HTTP server project (http://www.apache.org/)."
*
* 4. The names "Apache Server" and "Apache Group" must not be used to
*    endorse or promote products derived from this software without
*    prior written permission. For written permission, please contact
*    apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
*    nor may "Apache" appear in their names without prior written
*    permission of the Apache Group.
*
* 6. Redistributions of any form whatsoever must retain the following
*    acknowledgment:
*    "This product includes software developed by the Apache Group
*    for use in the Apache HTTP server project (http://www.apache.org/)."
*
* THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE APACHE GROUP OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Group and was originally based
* on public domain software written at the National Center for
* Supercomputing Applications, University of Illinois, Urbana-Champaign.
* For more information on the Apache Group and the Apache HTTP server
* project, please see <http://www.apache.org/>.
*
*/

/* Base64 encoder/decoder. Originally Apache file ap_base64.c
*/

#include "stdafx.h"
#include <string.h>

#include "base64.h"

namespace my_Base64
{

/* aaaack but it's fast and const should make it shared text page. */
static const unsigned char pr2six[256] =
{
    /* ASCII table */
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 62, 64, 64, 64, 63,
    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 64, 64, 64, 64, 64,
    64,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 64, 64, 64, 64, 64,
    64, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64
};

unsigned long Base64decode_len(const char *bufcoded)
{
    unsigned long nbytesdecoded;
    register const unsigned char *bufin;
    register unsigned long nprbytes;

    bufin = (const unsigned char *) bufcoded;
    while (pr2six[*(bufin++)] <= 63);

    nprbytes = (unsigned long)((bufin - (const unsigned char *) bufcoded) - 1);
    nbytesdecoded = ((nprbytes + 3) / 4) * 3;

    return nbytesdecoded;
}

unsigned long Base64decode(unsigned char *bufplain, const char *bufcoded)
{
    unsigned long nbytesdecoded;
    register const unsigned char *bufin;
    register unsigned char *bufout;
    register unsigned long nprbytes;

    bufin = (const unsigned char *) bufcoded;
    while (pr2six[*(bufin++)] <= 63);
    nprbytes = (unsigned long)((bufin - (const unsigned char *) bufcoded) - 1);
    nbytesdecoded = ((nprbytes + 3) / 4) * 3;

    bufout = bufplain;
    bufin = (const unsigned char *) bufcoded;

    while (nprbytes > 4) {
        *(bufout++) =
            (unsigned char) (pr2six[*bufin] << 2 | pr2six[bufin[1]] >> 4);
        *(bufout++) =
            (unsigned char) (pr2six[bufin[1]] << 4 | pr2six[bufin[2]] >> 2);
        *(bufout++) =
            (unsigned char) (pr2six[bufin[2]] << 6 | pr2six[bufin[3]]);
        bufin += 4;
        nprbytes -= 4;
    }

    /* Note: (nprbytes == 1) would be an error, so just ingore that case */
    if (nprbytes > 1) {
        *(bufout++) =
            (unsigned char) (pr2six[*bufin] << 2 | pr2six[bufin[1]] >> 4);
    }
    if (nprbytes > 2) {
        *(bufout++) =
            (unsigned char) (pr2six[bufin[1]] << 4 | pr2six[bufin[2]] >> 2);
    }
    if (nprbytes > 3) {
        *(bufout++) =
            (unsigned char) (pr2six[bufin[2]] << 6 | pr2six[bufin[3]]);
    }
    nbytesdecoded -= (4 - nprbytes) & 3;
    return nbytesdecoded;
}

static const char basis_64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

unsigned long Base64encode_len(unsigned long len)
{
    return ((len + 2) / 3 * 4);
}

unsigned long Base64encode(char *encoded, const unsigned char *string, unsigned long len)
{
    unsigned long i;
    char *p;

    p = encoded;
    for (i = 0; i < len - 2; i += 3) {
        *p++ = basis_64[(string[i] >> 2) & 0x3F];
        *p++ = basis_64[((string[i] & 0x3) << 4) |
            ((unsigned long) (string[i + 1] & 0xF0) >> 4)];
        *p++ = basis_64[((string[i + 1] & 0xF) << 2) |
            ((unsigned long) (string[i + 2] & 0xC0) >> 6)];
        *p++ = basis_64[string[i + 2] & 0x3F];
    }
    if (i < len) {
        *p++ = basis_64[(string[i] >> 2) & 0x3F];
        if (i == (len - 1)) {
            *p++ = basis_64[((string[i] & 0x3) << 4)];
            *p++ = '=';
        }
        else {
            *p++ = basis_64[((string[i] & 0x3) << 4) |
                ((unsigned long) (string[i + 1] & 0xF0) >> 4)];
            *p++ = basis_64[((string[i + 1] & 0xF) << 2)];
        }
        *p++ = '=';
    }
    return (unsigned long)(p - encoded);
}

std::string base64_encode(const unsigned char* bytes_to_encode, unsigned long in_len) 
{
    std::string result;
    ATL::CTempBuffer<char> buf;

    unsigned bufLen = Base64encode_len(in_len);

    if (!buf.Allocate(bufLen))
    {
        throw std::bad_alloc();
    }
    unsigned long encLen = Base64encode(buf, bytes_to_encode, in_len);
    ATLASSERT(bufLen >= encLen);
    return std::string(buf, encLen);
}

unsigned long base64_decode(const std::string& encoded_string, ATL::CTempBuffer<unsigned char>* ret /*= NULL*/, unsigned long nBuf /*= 0*/) 
{
    unsigned long bufLen = Base64decode_len(encoded_string.c_str());

    if (ret)
    {
        if (bufLen > nBuf)
        {
            if (!ret->Reallocate(bufLen))
            {
                throw std::bad_alloc();
            }
        }
        unsigned long decLen = Base64decode(*ret, encoded_string.c_str());
        ATLASSERT(decLen <= bufLen);
        return decLen;
    }
    return bufLen;
}

}